Objective: To determine the frequency of the estrogen receptor b gene (ERβ) +1730 G/A polymorphism in infertile women with and without endometriosis and controls.
Subjects and methods: Case-control study that included 136 women with endometriosis, 69 women without endometriosis and 209 fertile women as controls. The ERβ gene + 1730 G/A polymorphism was identified by RFLP-PCR (Restriction Fragment Length Polymorphism - Polymerase Chain Reaction).
Results: Genotypes GG, GA and AA of the ERβ gene presented frequencies of 60.3%, 38.2% and 1.5%, respectively, in the women with endometriosis (p < 0.0022). Of the infertile women without endometriosis, 63.8% presented the normal homozygous genotype GG, 30.4% the GA heterozygous genotype, and 5.8% the homozygous mutated genotype AA (p < 0.0275). In the control group, 77.5% presented the normal homozygous genotype GG, 21.1% the heterozygous genotype GA, and 1.4% the homozygous mutated genotype AA.
Conclusion: The data suggest that the estrogen receptor β gene (ERβ) +1730 G/A polymorphism can be associated with risk of infertility and endometriosis-associated infertility.